The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Imaging techniques have been used to image various portions of the human anatomy. Imaging techniques include ionizing radiation, producing fields relative to a human anatomy, etc. For example, x-ray imaging techniques include directing radiation through an anatomy and receiving a selected portion of the radiation on a film or collecting surface. Other types of imaging include producing fields relative to an anatomy, such as a magnetic field (e.g. magnetic resonance imager (MRI)), and sensing a change in atomic particles of the anatomy induced by the fields.
Various techniques can be used to acquire information relating to an anatomy, such as a human anatomy. For example, a MRI, which uses magnetic fields and radio frequency energy, can be used to acquire information regarding diffusion of various components or matter within the anatomy, such as water. Matter, such as water, can diffuse in the anatomy according to various principles, including Brownian motion. Diffusion can be anisotropic or isotropic. Anisotropic diffusion is generally along a selected path based upon restrictions on movement of the water, such as due to muscle fibers, fiber tracts in the brain, or other features. The anisotropic movement of the water can be defined based upon a tensor defining the motion or average motion of water within a voxel being imaged with a MRI. The MRI can be used to detect or determine the diffusion based on an attenuation of the MRI signal due to the diffusion of the water. Further analysis or processing can be used to determine a tensor based upon the movement of the water as it diffuses over time. Quick successive pulses of a MRI system can be used acquire data to determine the movement of water. The tensor can be used to determine information regarding the data, such as an Eigenvalue or Eigenvector, relating to the movement. The Eigenvector can define the average movement of water within a selected voxel of the MRI data. A more detailed discussion of DTI data acquisition and processing is discussed in Bihan et al., Diffusion Tensor Imager: Concept and Applications, Journal and Magnetic Resonance Imaging, 13, 534-546 (2001).
As discussed above, diffusion data from a MRI can be used to determine movement of water and the information can be used to illustrate the movement of the water on image data. The movement of water within a particular voxel can also be used to identify selected anatomical structures, such as fiber tracts. Various algorithms or techniques can be used to identify fiber tracts within the anatomy. Diffusion tensor image data, however, is substantially non-invasive and the tract developed based on the data includes only a certain amount of confidence.